GSMBE生长In_(0.49)Ga_(0.51)P/GaAs HBT微结构材料及器件研究

采用 GSMBE技术 ,在材料表征和分析的基础上 ,通过优化生长条件 ,生长出高性能In0 .4 9Ga0 .51P/ Ga As异质结双极晶体管 (HBT)微结构材料 ,并制备出器件。材料结构中采用了厚度为 6 0 nm、掺杂浓度为 3× 10 19cm-3的掺 Be Ga As基区和 5nm非掺杂隔离层 ,器件流片中采用湿法化学腐蚀制作台面结构。测试结果表明该类器件具有良好的结特性 ,在集电极电流密度 2 80 A/cm2时其共发射极电流增益达 32 0。由此说明非掺杂隔离层的引入有效地抑制了由于基区 Be扩散导致的 pn结与异质结偏位及其所引起的器件性能劣化。

Study of In0.49Ga0.51P/GaAs HBT Microstructure Materials and Devices Grown by GSMBE

This paper reports results of the high quality In 0.49 Ga 0.51 P/GaAs HBT microstructure materials and devices grown by GSMBE through optimizing the growth conditions. In material structure, a thin base layer has been grown with thickness of 60 nm and doped to a level of 3×10 19 cm -3 with beryllium. The thickness of undoped spacers is 5 nm. Conventional mesa structure was employed by using wet chemical etching technique. The fabricated HBTs reveal good junction characteristics and DC current voltage behavior, and the common emitter current gain reaches the value of 320 at collector current density of 280 A/cm 2. This result indicates that the undoped spacer suppresses diffusion of Be dopant and avoids the performance degradation introduced by the deflection between pn junction and heterojunction.